Nico Hulkenberg has admitted that life at his new team has been tougher than expected this year.

Hulkenberg switched from Force India to Sauber over the winter, but while Force India has made strides forward in 2013, Sauber has scored just five points. He said the team knows it is not quick enough and he is hoping it can improve in the second half of the season.

"It is tough and it hasn't worked as expected, but that's life," Hulkenberg said of his first six races with Sauber. "We just have to keep our heads down and focus on the current situation to improve the car and make it faster. There is still the second half of the season and we have to try to get better results and more points there."

Sauber brought a number of updates to Monaco and has done so again in Montreal this weekend, but due to the natures of the circuits it is hard to gauge how much of a step forward the team has made. Silverstone should give a better indicator of the team's progress, but Hulkenberg said that within the team everyone knows what the problems are.

"I don't think we need Silverstone to tell us, we know now that we are not quick enough and where our issues are and where we need to improve," he said. "It's a work in progress and every team brings updates and improves the car and develops it, but I don't think we need that circuit to say again that that is where we are."

Hulkenberg added that he is not worried that he is still driving for a midfield team four years after his debut with Williams.

"After four years there are very few who have come in and been in a winning car. If you look at Jenson [Button], he was in Honda for a number of years and not able to show his ability because the car was not good enough. Of course as a driver you always wish and would love to have a car that can show what you can do, but you have to be patient."